Chain stitch sewing machine



1936- H. J. LE VESCONTE CHAIN STITCH SEWING MACHINE Filed NOV. 6,,1955 3 Sheets$heet l 'l llllll lllll V 1936- H.' J. LE VESCONTE CHAIN STITCH SEWING MACHINE Filed Nov. 6, 1955 3 Sheets-Sheet 2 gun H. J. LE VESCONTE CHAIN STITCH SEWING MACHINE Filed NOV. 6, 1933 3 Sheets-Sheet 3 looper thread loop.

Patented Jan. 28 1936 STATES PATNT FFEQE CHAIN STITCH SEWING MACHINE Application November 6, 1933, Serial No. 696,889

provements in sewing machines, and more particularly to a sewing machine having a needle and a thread carrying looper cooperating to produce chain stitches.

An object of the invention is to provide a machine of the above type having a thread carrying looper moving back and forth in a single plane,

wherein the path of movement of the looper is such that the feed of the fabric will carry the portion of the looper thread extending from the eye of the looper to the previous stitch away from the body of the looper and thus permit the needle to pass between such portion of thelooper thread and said looper body as said needle enters the A further object of the invention is to provide a looper operating mechanism for imparting the above movements to a looper, which mechanism is so constructed as to permit a series of needles to be set abreast and very close together with a thread carrying looper cooperating with each needle.

In the drawings which show by way of illustration one embodiment of the invention Figure 1 is a view partly in vertical section and partly in front elevation showing a portion of a sewing machine embodying the improvements;

Fig. 2 is a plan view of the parts beneath the work support;

Fig. 3 is a plan View of the looper operating mechanism showing the looper retracted;

Fig. 4 is a View partly in vertical section and partly in front elevation of a portion of the looper mechanism shown in Fig. 3;

Fig. 5 is a sectional view on the line 55 of Fig. 3;

Fig. 6 is a sectional view on the line 6-6 of Fig. 2;

Fig. 7 is a view showing more or less diagrammatically the position of the needle, the looper and the direction of feed, with the looper at the forward end of its stroke and the needle at the upper end of its stroke, and

' Fig. 8 is'a view similar to Fig. 7, but showing the looper partly retracted and'the needle as entering the looper thread loop.

The invention is directed to a sewing machine which is provided with a needle and, a thread carrying looper for producing chain stitches. As illustrated, the invention is shown as applied to a multiple needle machine wherein the needles are set abreast. Each looper, however, cooperates independently with the needle with which it is associated, and therefore, independent lines of stitching are produced. The invention may be used in a single needle machine.

The sewing machine includes a supporting bed I carrying a supporting frame 2 on which is mounted a throat plate 3. The cloth plate is also mounted on this supporting frame 2 and surrounds the throat plate. Mounted on the bed I is the usual standard and overhanging arm carrying the needle head 4 in which the needle bar 5 reciprocates. Said needle bar, as shown, is provided with a cross bar 6 carrying needles I, 3, 9, and I0. Also mounted in the needle head is a presser bar I I carrying a presser foot I2.

The material is fed beneath the presser foot I2 by means of a. feed dog I3 carried by a feed bar I4 which is attached to a feed rocker I5, and the feed rocker 'I 5 is oscillated by an arm I6 connected to a crank on the outer end of the main actuating shaft I I. The feed bar is raised and lowered by the usual eccentric on the actuating shaft. This feeding mechanism is of the usual construction, and in their operation, the feed dogs move upwardly through slots in the throat plate into contact with the material beneath the presser foot and moves the material past the needles.

Cooperating with the needle I is a thread carrying looper I 8. There is a thread carrying looper I9 which cooperates with-the needle 8, a thread carrying looper 20 cooperating with the needle 9, and a thread carrying looper 2| which cooperates with the needle In. These loopers are mounted on an arm 22 carried by a looper carrier 23. The looper carrier 23 includes a sleeve 24 which is fixed to a shaft 25. The shaft 25 is mounted for endwise movement in brackets 26 and 21 attached to a plate 28 which is in turn secured to the bed I of the machine.

Depending from the sleeve 24 is an arm 29 which is provided with a rectangular head adapted to slide between the guide bars 33 and 3I.

These guide bars are secured to the plate 28 by suitable screws 32, 32. This provides a looper supporting means which carries the loopers back and forth in a right line and in a single plane. The needles I, 8, 9, and II] are set abreast, that is, in a line at right angles to the line of feed. The longitudinal axis of the shaft 25 lies in a vertical plane cutting the vertical plane containing the line of feed at an acute angle.

The shaft 25 and the looper carrier are moved back and forth by means of a lever arm 33. Said lever arm 33 is carried by a sleeve 34 mounted for oscillation on a vertical post 35 attached to the bed I of the machine. A link 36 is pivoted at 31 to this lever arm 33, and at 38 to a lug 39 projecting from the sleeve 24. Also mounted on the post is a sleeve 40 which is provided with a notch or recess 41a adapted to receive a lug 42 carried by the sleeve 34. A spring 43 bearing against the sleeve 40 and the head 4! of the post 35, yieldingly forces the sleeve 40 downward so as to bring said lug into the recess and thus lock together the sleeves 34 and 4E Said sleeve 40 carries an arm 44 which is provided with a slot 45. A ball stud 46 is mounted for adjustment in the slot 45. An eccentric strap 41 cooperating with an eccentric 48 on the main actuating shaft I1 is attached to the ball stud 46. As the shaft rotates, the eccentric will produce an endwise movement in the eccentric strap which will oscillate the arm 44, and this will in turn impart oscillations to the lever arm 33 and move the looper carrier and its supporting shaft 25 back and forth. I The loopers are all similar in construction and cooperate in a similar manner with their associated needle, and the description of one will answer for the others. .Each looper includes a shank which is secured to the arm 22 of the looper carrier. The shank extends laterally, thence upwardly, and again laterally to form the body portion 49 of the looper. There is an eye 50 at the outer end of the looper body through which the thread is passed, and a. thread groove 51 leading therefrom along the side of the looper. This is the usual construction of a thread carrying looper. The thread passes into the groove at the heel of the looper, or inner end of the body portion and then along the grooveand through the eye 50 thereof. The thread extends from the eye 58 of the looper to the enchained thread loops, and from the heel of the looper to the thread supply. The looper body is made very slender and relatively thin compared with the shank of the looper, all the way from the heel of the looper to the point thereof. Each needle is provided with a thread eye of the usual type. The needle thread which is indicated at it passes from the supply down the side of the needle, thence through the eye of the needle, and to the enchained thread loops. The eye of the needle, as shown in Figures 7 and 8, is disposed in a line which is substantially at right angles to the path of movement of the looper. The looper path is in a line at an acute angle to the line of feed. The looper always passes the needle on the same side thereof. The looper eye moves from a point in rear ofthe needle as viewed in the line of feed, and at the right thereof to a point in front of the needle and at the left thereof. The needle eyeis threaded from the rear toward the front, and therefore, when the looper moves forward, the point there of will pass into the needle thread loop. The looper thread is indicated at Z. The previous needle puncture is indicated at n, and the feed of the fabric is in the direction of the arrow at in Fig. 7. The needle in Fig. 7 is at the upper end of its stroke, and the looper is at the forward end of its stroke. The feed has taken place, and the previous needle puncture n has moved rearwardly so that the fabric is positioned for the entrance of the needle into the same. During this feed of the fabric, the portion 1' of the looper thread between the eye 50 of the looper and the previous stitch formation is carried away from the body of the looper or separated therefrom, so that the needle may pass between this portion Z and the body of the looper on its descent. In Fig. 8, the needle point is shown well down into the thread triangle formed by the body of the looper, the portion Z and the previous needle thread loop which is indicated at 12 This completes the entrance of the needle into the looper thread loop and the enchaining of the thread loops for the stitch formation.

It will be noted that the looper moves back.

and forth in a straight line and in a single plane, and therefore, the looper may be reciprocated very rapidly for high speed stitching. The usual lateral movement of the looper to open the thread triangle is not necessary, for the reason that the feed as it moves the fabric with the enchained thread loops attached thereto accomplishes this spreading of the thread triangle for the needle to enter. Inasmuch as the looper is inclined from rear to front away from the line of feed, the thread loop 12 on the body of the looper will tend to slip away from the needle and the line of feed when. under. tension, and therefore, the feed of the fabric also tends to force the needle thread loop 11 back on the looper at the same time that it carries the portion I of the looper thread awayfrom the body of the looper. This makes a very wide open thread triangle for the needle to enter.

What has been said in connection with the looper cooperating with the needle I, applies equally to the loopers cooperating with the other needles. occupies very little lateral space inits path of travel. Therefore, the needles I and,8 may be placed very close together, and the looper IS lines and the looper is mounted thereon to move 7 back and forth likewise in right lines. There is no lateral movement, or combination ofback and.

forth and lateral movements given to the looper, as is usual in a chain stitch machine, in order to accomplish the opening of the thread triangle.

The body of the looper is slender and will pass between the needles while it cooperates Neither is there any additional spreader element required for the opening of the threadtriangle. It is all accomplished by the cooperative action of the movements of the looper back and forth in a right line, and the movements of the fabric forward in a right line as the material is fed a stitch length.

The purpose of the interlocking lug and recess connection between the sleeves 4i! and 34 is to allow the sleeve 40 to be lifted and disconnected from the sleeve 34 so that the loopers can be moved forward to facilitate the threading of the same. This feature in the looper operating mechanism which permits the shifting of the loopers for threading forms no part of the present invention, but is shown, described and'claimed in an application filed by Hans Hacklander, filed November 20, 1933, Serial No. 698,891.

It is obvious that minor changes in the details of construction and the arrangement of the parts may be made without departing from the spirit.

said looper back and forth in a single plane, said M supporting and moving'means being disposed so that the looper eye moves from a position in rear of the needle and at one side of a vertical plane containing the needle and parallel to the line of feed to a position in front of the needle and at the other side of said plane as it enters the needle thread loop, said looper penetrating said vertical plane in front of the path of the needle.

2. In a sewing machine, the combination of a needle, a feeding mechanism for feeding the material, a thread carrying looper cooperating with said needle, a looper carrier on which said looper is mounted, means for bodily moving said carrier back and forth in a single plane, said carrier and moving means being disposed so that the looper eye moves from a position in rear of the needle at one side of a vertical plane containing the needle and parallel to the line of feed to a position in front of the needle and at the other side of said plane as it enters the needle thread loop, said looper penetrating said vertical plane in front of the path of the needle.

3. In a sewing machine, the combination of a needle, a feeding mechanism for feeding the material, a thread carrying looper cooperating. with said needle, a looper carrier on which said looper is mounted, an endwise moving shaft to which said carrier is attached, a depending member carried by said shaft, guiding means for guiding the depending member so that the looper moves back and forth in a single plane, and means for moving said shaft back and forth for causing the looper eye to move from a position in rear of the needle at one side of a vertical plane containing the needle and parallel to the line of feed to a position in front of the needle at the other side of the said plane as it enters the needle thread loop.

4. In a sewing machine, the combination of a needle, a feeding mechanism for feeding the material, a thread carrying looper cooperating with said needle, a looper carrier on which said looper is mounted, a shaft, bearings in which said shaft is adapted to move endwise, said looper carrier being attached to said shaft, an arm depending from said shaft, guides between which said arm moves when said shaft is moved endwise for preventing lateral movement of the looper, said shaft being disposed in a plane cutting the line of feed at an acute angle, and said looper being disposed so that the eye of the looper will move from a position in rear of the needle at one side of a vertical plane containing the needle and parallel to the line of feed to a position in front of the needle at the other side of said plane as it enters the needle thread loop, and means for moving said shaft in an endwise direction.

5. In a sewing machine, the combination of a needle, a feeding mechanism for feeding the material, a thread carrying looper cooperating with said needle, a looper carrier on which said looper is mounted, a shaft, bearings in which said shaft is adapted to move endwise, said looper carrier being attached to said shaft, an arm depending from said shaft, guides between which said arm moves when said shaft is moved endwise for preventing lateral movement of the looper, said, shaft being disposed in a plane cutting the line of feed at an acute angle, and said looper being disposed so that the eye of the looper will move from a position in rear of the needle at one side of a vertical plane containing the needle and parallel to the line of feed to a position in front of the needle at the other side of said plane as it enters the needle thread loop, a main actuating shaft, a member connected to said looper carrier supporting shaft for moving the same endwise, said member being mounted for oscillation about a vertical axis, and means operated by said actua'ting shaft for oscillating said member.

6. In a sewing machine, the combination of a needle, a feeding mechanism for feeding the material, a thread carrying looper cooperating with said needle, a looper carrier on which said looper is mounted, a shaft, bearings in which said shaft is adapted to move endwise, said looper carrier being attached to said shaft, an arm depending from said shaft, guides between which said arm moves when said shaft is moved endwise for preventing lateral movement of the looper, said shaft being disposed in a plane cutting the line of feed at an acute angle, and said looper being disposed so that the eye of the looper will move from a position in rear of the needle at one side of a vertical plane containing the needle and parallel to the line of feed to a position in front of the needle at the other side of said plane as it enters the needle thread loop, a lever arm mounted for oscillation about a vertical axis, a link connecting said lever arm with said shaft supporting the carrier for moving said shaft endwise, an arm connected to said lever arm for oscillating the same about its axis, an actuating shaft, an eccentric on said actuating shaft, and an eccentric strap cooperating therewith and connected to the actuating arm for oscillating said lever arm.

7. In a sewing machine, the combination of a plurality of needles set abreast, a feeding mechanism for feeding the material, a thread carrying looper associated with each needle, a looper carrier on which all of said loopers are mounted, means for supporting said carrier and for moving the same back and forth in a single plane whereby the eye of each looper is moved from a position in rear of its associated needle and at one side of a vertical plane parallel to the line of feed and containing said needle to a position in front of its associated needle and at the other side of the said plane, whereby the feed of the fabric will separate the looper threads extending from the eyes of the loopers to the previous stitches from the bodies of the loopers so as to permit the needles to enter their respective thread triangles.

8. In a sewing machine, the combination with a plurality of needles set abreast, a feeding mechanism for feeding the material, a thread carrying looper cooperating with each needle, a looper carrier on which all of said loopers are mounted, a shaft mounted for endwise movement, means for fixedly supporting said looper carrier on said shaft, an arm depending from said shaft, guide bars for guiding the lower end of said arm and preventing said loopers from lateral movement, and means for moving said shaft endwise, said shaft being disposed so that each looper is moved back and forth in a single straight line path of travel cutting a vertical plane parallel to the line of feed and containing the needle with which said looper is associated at an acute angle and placing the eye of said looper at the forward end of its stroke in front of its associated needle and at the opposite side of said vertical plane whereby the feed of the fabric will separate each looper thread extending from the eye of the looper to the previous stitch from the body portion of the looper with which it is associated so as to permit the needles to enter their respective thread triangles.

9. In a sewing machine, the combination of a .feeding mechanism, a needle having the'eye arranged in a line cutting the line of feed at an acute angle, a thread carrying looper mounted for movement back and forth in a straight line cutting the line passing through the eye of the needle at right angles and the line of feed at an acute angle, the eye of said looper when said looper is at the forward end of its'stroke being in front of the needle and at one side of a plane passing through the needle parallel with the line of feed whereby the looper thread running from the eye of the looper to the previous stitch is separated from the body of the looper to permit the needle to enter the looper thread loop.

10. In a sewing machine, the combination of a needle, a feeding mechanismfor feeding the material, a thread carrying looper cooperating with said needle, means for supporting and moving said looper back and forth in a single plane, said supporting and moving means being disposed so that the loOper eye moves from a'position in rear of the needle and at one side of a plane containing the needle parallel to the line of feed to a position in front of the needle and at the other side of said plane as it enters the needle thread loop and with the path of the looper eye on the side of the needle remote from the side at which the stitch is completed.

HAROLD J. LE VES CONTE. 

